- John Taolo Gaetsewe District Municipality
- Joe Morolong Local Municipality
| [var. Chalcedony] Preston, P. C. C. R. (2009). Physical and chemical characterization of the manganese ore bed at the Mamatwan mine, Kalahari manganese field (Doctoral dissertation). Gutzmer, J. (1996). Genesis and alteration of the Kalahari and Postmasburg manganese deposits, Griqualand West, South Africa (Doctoral dissertation, Rand Afrikaans University). Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, Linden . |